Switching display update properties upon detecting a power management event

Abstract

Systems and methods provide automatic switching of display update properties such as screen resolution, pixel depth, and refresh rate in response to a power management event. The display update property may be decreased when power is switched from AC power to DC power, for example, when the system is unplugged from a wall outlet and is running on battery power.

1. A method comprising:
 detecting a power management event; 
 selecting a policy from a plurality of power management policies, wherein the selected policy matches the power management event; and 
 changing a display update property for a video display in response to the power management event, the display update property comprising at least one of a screen resolution or a pixel depth, wherein changing the display update property includes changing the display update property in accordance with the selected policy. 
 
     
     
       2. The method of  claim 1 , wherein the detecting the power management event includes detecting a change in a power source from AC power to DC power and wherein changing the display update property includes decreasing the display update property. 
     
     
       3. The method of  claim 1 , wherein the detecting the power management event includes detecting a change in a power source from DC power to AC power and wherein changing the display update property includes increasing the display update property. 
     
     
       4. The method of  claim 1 , wherein the detecting the power management event includes detecting a decrease in a power level of a battery past a predetermined threshold and wherein changing the display update property includes decreasing the display update property. 
     
     
       5. The method of  claim 1 , wherein the detecting the power management event includes detecting an increase in a power level of a battery past a predetermined threshold and wherein changing the display update property includes increasing the display update property. 
     
     
       6. A system comprising:
 a processor; 
 a graphics controller coupled to the processor; and 
 a frame buffer coupled to the graphics controller, said frame buffer having a size corresponding to a screen resolution and a pixel depth; 
 wherein the processor is operable to:
 detect a power management event; 
 select a policy from a plurality of power management policies, wherein the selected policy matches the power management event, and 
 change the screen resolution in response to the power management event, wherein the processor is operable to change the screen resolution in accordance with the selected policy. 
 
 
     
     
       7. The system of  claim 6 , wherein the power management event includes a change in a power source from AC power to DC power and further wherein the processor is operable to decrease the screen resolution. 
     
     
       8. The system of  claim 6 , wherein the power management event includes a change in a power source from AC power to DC power and further wherein the processor is operable to decrease the pixel depth. 
     
     
       9. The system of  claim 6 , wherein the power management event includes a change in a power source from DC power to AC power and wherein the processor is operable to increase the screen resolution. 
     
     
       10. The system of  claim 6 , wherein the power management event includes a change in a power source from DC power to AC power and further wherein the processor is operable to increase the pixel depth. 
     
     
       11. The system of  claim 6 , wherein the power management event includes a decrease in a power level of a battery past a predetermined threshold and wherein the processor is operable to decrease the screen resolution. 
     
     
       12. The system of  claim 6 , wherein the power management event includes an increase in a power level of a battery past a predetermined threshold and wherein the processor is operable to increase the screen resolution. 
     
     
       13. The system of  claim 6  further comprising:
 a memory controller; and 
 a system memory coupled to the memory controller; 
 wherein the frame buffer resides in the system memory. 
 
     
     
       14. The system of  claim 13 , wherein the graphics controller and the memory controller are integrated into a single chipset. 
     
     
       15. A machine-readable medium having machine executable instructions for performing a method comprising:
 detecting a power management event; 
 selecting a policy from a plurality of power management policies, wherein the selected policy matches the power management event; and 
 changing a display update property for a video display in response to the power management event, the display update property comprising at least one of a screen resolution or a pixel depth, wherein changing the display update property includes changing the display update property in accordance with the selected policy. 
 
     
     
       16. The machine readable medium of  claim 15 , wherein the detecting the power management event includes detecting a change in a power source from AC power to DC power and wherein changing the display update property includes decreasing the display update property. 
     
     
       17. The machine readable medium of  claim 15 , wherein the detecting the power management event includes detecting a change in a power source from DC power to AC power and wherein changing the display update property includes increasing the display update property. 
     
     
       18. The machine readable medium of  claim 15 , wherein the detecting the power management event includes detecting a decrease in a power level of a battery past a predetermined threshold and wherein changing the display update property includes decreasing the display update property. 
     
     
       19. The machine readable medium of  claim 15 , wherein the detecting the power management event includes detecting an increase in a power level of a battery past a predetermined threshold and wherein changing the display update property includes increasing the display update property.